1. Field of the Invention
The present invention relates to a light intercepting mechanism of a zoom lens barrel.
2. Description of the Related Art
In a known zoom lens barrel, particularly a zoom lens barrel of a zoom compact camera, a movable lens frame (moveable lens barrel) which holds a frontmost lens group is surrounded by a drive ring (e.g., cam ring) which is relatively rotatable, so that the movable lens barrel is moved in an optical axis direction by a relative rotation of the drive ring.
Generally, in this type of zoom lens barrel, an annular light intercepting member in the form of paper or tape, etc., is attached to the inner peripheral surface of the front end of the drive ring. The annular light intercepting member is brought into sliding contact with the outer peripheral surface of the movable lens frame to thereby prevent extraneous (harmful) light from entering through an annular gap between the movable lens frame and the drive ring.
However, in the conventional light intercepting mechanism as mentioned above, the annular light intercepting member has a certain length in the optical axis direction, and hence the decrease in the axial length of the zoom lens barrel and accordingly the thickness (length in the optical axis direction) of the camera is limited to some extent by the light intercepting member.
In addition, there is no zoom compact camera hitherto known, having a lens hood incorporated therein.
As is well known, a lens hood is adapted to prevent intensive extraneous light out of the angle of view from entering the lens, for example when a picture is taken against the backlight. If the external light enters the lens, lenflare is caused by the internal reflections of the extraneous light within the lens barrel. Consequently, image quality deteriorates.
For instance, a zoom lens for a single lens reflex camera may have a built-in cylindrical lens hood. The cylindrical lens hood is slidably fitted onto the outer peripheral surface of the lens barrel. The lens hood is retracted rearward during storage and is manually advanced forward when the lens is used. The advantages of a lens hood would also benefit a compact camera.
However, it is difficult to apply the above-mentioned structure for a single lens reflex detachable lens to a compact camera in which the lens barrel is entirely accommodated in the camera body. Alternatively, if a separate lens hood is detachably attached to the front end of the lens by means of a bayonet or screw coupling, it is necessary for a photographer to carry a separate lens hood. However, this reduces one of the main attractions of a compact camera, that is portability.